Since the 1990s, simulation and organizational studies have been conducted in Japan. In this paper, we review the simulation and organizational studies in Japan, including the relationships between researchers. The global trend is to cite the results of simulation studies as metaphors. By contrast, in Japan, there are unique research groups which critically examine the existing models, perform simulations, and further test them against survey data. The lessons they learned are: (a) The animation of the simulation results stir the imagination of researchers and business persons. However, (b) if the phenomena indicated by simulation and the reality of parameter values are not supported by the survey data, the implications derived from simulation are no more than a delusion.